Chapter 46: Command Line Descriptions
STANDARD Revision 1.0
C4® CMTS Release 8.3 User Guide
© 2016 ARRIS Enterprises LLC. All Rights Reserved.
1577
configure interface cable-mac * cable upstream ext-power
Purpose
Enables the extended CM transmit power before and after registration.
Default Access Level
15
Command Syntax
configure interface cable-mac <mac> cable upstream ext-power [<pre-reg | post-reg>]
configure interface cable-mac <mac> cable upstream ext-power no
Supplemental
Information
The DOCSIS3.0 specifications increased the total transmit power for CMs by 3 dB when 4 channels are active in the transmit channel
set while also decreasing the power per channel by 3dB. This decrease in the channel power resulted in some disadvantages:
A)
Performance degradation in some deployments due to 3 dB loss in SNR.
B)
Inconvenience to MSOs, where they need to adjust the gain alignment on the return path to accommodate the decrease in
the CM channel transmit power before US channel bonding can be turned on.
To address the above issues, Cablelabs issued two ECNs [ECN_PHY] [ECN_MULPI] that enable CMs to extend their per-channel
transmit power beyond what was originally specified in the DOCSIS specifications [PHYv3.0] provided that the maximum channel
power does not exceed 61dBmV. This will allow the MSOs to maintain adequate SNR values while operating bonded QAM64
channels.
The default setting is disabled before registration and enabled after registration.
Note: If no argument is specified: the CM transmit power extension is enabled before and after registration.
pre-reg: the CM transmit power extension is enabled before registration and disables it after registration.
post-reg: the CM transmit power extension is enabled after registration and disables it before registration.
To disable the CM transmit power extension before and after registration, use the no option.
Parameters
<mac>
The MAC identifier. Valid numbers are 0-415.
<pre-reg>
Enables the CM transmit power extension before registration and disables it after registration.
<post-reg>
Enables the CM transmit power extension after registration and disables it before registration.